WASHINGTON, July 30 (Reuters) - More than 100 U.S. Republican donors and fundraisers called on conservatives in Congress to back an overhaul of the nation's immigration system, including supporting "legal status" for those in the United States illegally, the New York Times reported on Tuesday.

The Republicans, including former President George W. Bush's aide Karl Rove, told lawmakers in a letter that refusing to reform the immigration system amounted to "de facto amnesty," the newspaper said.

"Standing in the way of reform ensures that we perpetuate a broken system that stifles our economy, leave millions of people living in American unaccounted for, maintain a porous border, and risk a long-lasting perception that Republicans would rather see nothing done than pass needed reform," they said in the letter, a copy of which was posted on the newspaper's website.

"That is not the path for the Republican Party."

The effort was shepherded by former Secretary of Commerce Carlos Gutierrez, who also served under Bush, and included a variety of political donors and fundraisers who offered three mandates that should be included in final legislation:

"To fix our immigration system we need meaningful reforms that will (1) secure our borders, (2) provide a legal way for U.S.-based companies to hire the workers they need while making it impossible to hire workers here illegally, and (3) take control of our undocumented immigration problem by providing a path to legal status for undocumented immigrants who pay penalties and back taxes, pass criminal background checks, and go to the back of the line," the donors wrote.

Lawmakers are trying to work out a solution to overhaul the U.S. immigration system, including a plan to address the 11 million immigrants in the country illegally.

The Senate passed a sweeping reform bill in June, but House Republicans are deeply divided over the issue and have no clear strategy or timeline for passing their own legislation that could eventually be merged with the Senate bill.

White House spokesman Jay Carney has said he expects Congress will pass comprehensive immigration reform legislation that President Barack Obama will sign into law. (Reporting by Susan Heavey; editing by Christopher Wilson)